A NAND flash memory includes a memory cell region, a row decoder, a sense amplifier, and peripheral circuit parts. In the NAND flash memory, the sense amplifier is used to detect the presence or absence of cell current flowing through the memory cell, or the magnitude of the current, to determine whether the data bit is “0” or “1”. The sense amplifier is connected to a bit line to which a large number of memory cells are connected. An all bit line (ABL) sense amplifier has been proposed in which, during a sensing operation, the bit line potential is controlled so as to be at a fixed voltage, thereby mitigating effects on other adjacent bit lines. In this ABL sense amplifier, the sense node and the bit line are pre-charged, after which the electric charge in the capacitor of the sense node is discharged. Detecting the voltage level of the sense node after discharge determines the data bit to be “0” or “1”. In the ABL sense amplifier, the capacitor elements (sense amplifier capacitors) having same numbers as the numbers of bit lines are provided.